John l



June 18, 1929.

J. L. MOSHER AUTOMATIC ATMOSPHERIC PRESSURE BALANCER FOR BUILDINGS Filed Oct. 25, 1927 INVENTOR 2? BY M AT RNEY Patented June 18, 1929.

UNITED STATES JOHN L. MOSHER, OF ALBANY, NEW YORK.

AUTOMATIC ATMOSPHERIC-PRESSURE BALANCER FOR BUILDINGS.

Application filed October 25, 1927.

My present invention relates to a means for preventing the destruction of or damage to buildings by reason of a sudden reduction in the atmospheric pressure outside thereof to a .7 point considerably lower than that which pre- I vails inside, and which may occur with some frequency in the so-callcd cyclone belts.

Much of the damage which occurs during high winds or cyclones is caused by the sudlo den upsetting of the normal balance between the atmospheric pressures within and without the buildings. A sudden decrease in the pressure prevailing outside of a building, while the air-inside is confined as securely as usual, will often upset the balance to such a degree that the result thereof is a blowout of windows or other comparatively weal: portions of the buildings.

The obejct of this invention is to provide a means for preventing any upsetting of the atmospheric balance which causes the pres sure within a building to be greater than that without, from having any destructive effect thereon.

The manner in which I have accomplished my object is illustrated in the accompanying drawing, in which the figure represents a cross section through the wall of a building constructed for and/or equipped with my automatic pressure equalizing means.

Referring to the drawings, 2 indicates the wall of a building having an opening (or openings) formed therethrough, at least a portion of said opening (or openings) being intended as a pressure relief port and having a suitably hinged or pivoted cover or shutter 3 normally closing the same, said cover being so arranged or mounted that it is adapted to swing outwardly from the normal closed position, and preferably so that it will be held in closed position by gravity under any normal conditions. Some suitable means, as for example a ratchet 4 and pawl 5, is preferably provided for a purpose which will be hereinafter set forth.

In the drawings I have illustrated the opening covered by the hinged cover 3 as being located above and in juxtaposition to a usual window opening, and while I now believe this to be the preferred location it is of course Serial No. 228,653.

obvious that it could be located in the upper part of, or just above a door opening; or it could be entirely separate from other openmgs. It is also obvious that the hinged cover may be a glazed sash if so desired; and that the opening to be used as a relief port need. not be located in the vertical walls of a building but could be located in the roof or any other suitable place.

The covers 3 bein pivoted so that they may be swung outwardly but will normally be held closed by gravity, it being obvious that, being closed they will remain so as long as the atmospheric pressure on the two sides thereofremains substantially equal. If, now, the pressure on the two sides becomes unbalanced either by an increase of the pressure within or a decrease in the pressure without so that the pressure within the building becomes appreciably greater than that without, it is obvious that the effect of this unbalancing of the pressures will be to force the shutters outward so that the higher pressure within may escape without causing damage, and the balance to be automatically restored.

The pressure balance being restored after such an upset the shutters, unless restrained would naturally gravitate to the closed position; and as the upsetting of the balance may be caused by a sudden reduction of the outside pressure, which may be as suddenly restored, the shutter vhen swung open by reason of the upsetting of the pressure balance, unless presented from closing until deliberately released, might have imparted thereto a more or less rapid reciprocating motion which could cause damage. It is for the purpose of providing means for preventing such free movement that I prefer to provide the ratchet and pawl above mentioned.

\Vhile I now prefer to permit the shutter to swing comparatively free, it is obvious that a certain amount of restraint may be employed so that a predetermined amount of difference in pressure must be present before the shutter will open.

I claim:

Means actuated by atmospheric pressure within a building in excess of that without for automatically reducing such excess pressure, said means comprising an opening leading from the interior of the building to atmosphere; a cover for said opening normally held in closed position by gravity and adapted to be swung open Whenever the pressure inside is in excess to that Without to an appreciable degree, and automatically operating means for preventing said cover from returning to closed position when so opened. 10

In testimony whereof I have afiixed my signature.

JOHN L. MO SHER. 

